Ship&#39;s davit of the gravity type



June 20, 1944. p, sc -r 2,352,018

SHIPS DAVIT OF ,THE GRAVITY TYPE Filed May 16, 1940' Patented June 20,1944 v I: Ane' P. Schat, Utrecht, Netherlands; vested in Q i ,theAlienProperty Custodian audition May'16, 1940, Serial No. 335,629

. In Germany November 7, 19381 1 Claim. (01. 9-22) My present inventionrelates to ships davits of the gravity type, i. e. to davits comprisinga davit arm adapted to travel down an outwardly sloping track disposedsubstantially athwartships on the vessel and thereby to move from aninboard position into an outboard position exclusively under theinfluence of gravity. In certain types of gravity davit, the davit armhas its foot pivoted to a carriage adapted to run on the track and isthus adapted for outward swinging or lufiing movement in addition tooutward traveling movement, reference being had to my prior U. S. Patent2,141,452, dated December 27, 1938.

As to said track, it is desirable for the same to have a steepinclination, in order that the a boat may be readily launched even onthe high side of a ship having a heavy list. On the other hand, a steepinclination of the track means increased height of the boat above thewater line and consequently, apart from other drawbacks,

reduced stability of the ship.

The primary object of my present invention is a. gravity davit by meansof which the boat can be safely and quickly launched under practicallyall conditions and nevertheless be stowed at a relatively low level.With this and other objects in view, I suggest to provide for meanswhereby the slope of the davit arm track relative to the ships deckcan'be varied. preferably by pivoting the outer end portion of the trackto the ship so as to adapt it for transverse swinging movement, and byassociating the inner end portion thereof to the ship by a telescopicscrew gear such, for instance, as disclosed by my prior U. S. Patent2,044,403, dated June 16, 1936.

In order that my invention may be fully understood, I shall now proceedto describe the same with reference to the annexed more or lessdiagrammatic drawing, on which:

Fig. 1 is a front view of a life boat suspended from a gravity davit inaccordance with my invention, the inboard or stowed position being shownin full lines, two outboard positions being indicated in dotted lines,and

Fig. 2 is a similar front view of a somewhat different arrangement.

Figure 3 is a fragmentary perspective detail of a portion of the fall.

In Fig. l, the reference numeral 5(5) designates the life boat, 6(6')one of the two boat falls, and 1 the corresponding davit arm. The davitarm has an enlarged foot provided with rollers 8, through which it isadapted to run athwartships on an outwardly sloping track 9.

Said arm is thus capable, exclusively under the i action of gravity, totravel from its inboard position to its extreme outboard position.

Each boat fall 66' includes a cable extending from a winch not shown andtrained about a pulley wheel l6 mounted near the inner end of the track9 and thence trained about pulley wheels I! and I8 on the davit I andfinally trained over the pulley arrangement generally designated I9 inFig. 3 while the outer end of each cable is fixed as at 20 to the davitarm I, the arrangement being clearly shown in Figs. 1 and 3.

Detachably secured to the boat are a pair of skates I 0(l0'), whichserve for protecting the boat against damage during lowering and forguiding it over the ships side, as is well known in the art.

In accordance with my invention, the track 9, instead of being rigidlysecured to the vessel such as is the case in prior suggestions, ispivoted with its outer end to the deck I 2 as at I I, whereas its innerend portion is associated with the ship through a telescopic screw gearl4 hinged both to the deck and to the track, and adapted to be actuatedby means of a crank handle l3.

Assuming the ship to have an appreciable list and the boat illustratedto be on the high side thereof, the slope of the track 9 in its lowerposition, as indicated by full lines, may be so small as not to allowthe davit arm I with the boat 5 suspended therefrom to move outward bygravity only. In that case all that is required is increasing the slopeof the track 9 by turning the crank handle l3 until the screw gear [4has forced the track into a position wherein the slope of the latter issteep enough for causing the davit arm with the parts associatedtherewith to travel towards the water.

In its normal or lower position the track 9 has a slope, which justallows the boat to move outward by gravity on the high side of a shiphaving a list of say 10. With this relatively small slope, the stowedboat may be arranged to assume a position only slightly above the deckI2. The distance through which, in the extreme outboard position of thedavit arm I on its track 9, the davit head projects laterally from theship's side increases with the slope of the track. This clearly followsfrom Fig. 1 of the drawing, which shows that with the track 9 in itsnormal or lower position and in the position indicated by dotted linesthe davit arm will assume positions A and B, respectively. The drawingfurther shows that with the davit arm in position A, the aforesaiddistance is smaller than half curves toward the vertical as itapproaches its 7 pivotal point I I. This results in the tilting outwardof the davit arm as it approaches its lower position and assists inswinging the boat clear of the hull. 7

According to Fig. 2, the track 9 is mounted at a level as to provide fora passageway between it and the deck l2. In said figure, like parts aredesignated by the same reference numerals asin Fig. 1.

What I claim is:

In combination an outwardly and downwardly sloped track to be disposedsubstantially athwartships on a vessel and having the lower end thereofpivoted to the vessel, said track being downwardly curved near its lowerend, a gear mounted on the vessel and outwardly connected to the trackat a point other than its pivotal point for adjusting the slope of thetrack, a davit arm mounted for traveling movement on said track, spacedrollers for guiding the arm on the track, a fall for suspending the boatfrom the davit arm and roven whereby the davit arm may travel downwardlywhen the fall is paid out and will force the davit arm upwardly when thefall is hauled in and whereby the slope of the track is adjustedindependently of the fall and the davit arm is tilted outwardly as itapproaches the lower end of the track.

ANE P. SCI-TAT.

